165781690323 has 4 divisors (see below), whose sum is σ = 221042253768. Its totient is φ = 110521126880.

The previous prime is 165781690303. The next prime is 165781690367. The reversal of 165781690323 is 323096187561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165781690323 - 2⁶ = 165781690259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165781690303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27630281718 + ... + 27630281723.

It is an arithmetic number, because the mean of its divisors is an integer number (55260563442).

Almost surely, 2^165781690323 is an apocalyptic number.

165781690323 is a deficient number, since it is larger than the sum of its proper divisors (55260563445).

165781690323 is an equidigital number, since it uses as much as digits as its factorization.

165781690323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55260563444.

The product of its (nonzero) digits is 1632960, while the sum is 51.

The spelling of 165781690323 in words is "one hundred sixty-five billion, seven hundred eighty-one million, six hundred ninety thousand, three hundred twenty-three".